/usr/lib/python3/dist-packages/aptdaemon/client.py has this at line 40:

if 'gi.repository' in sys.modules:
from gi.repository import GObject
else:
import gobject as GObject

I don't know if it should be getting it from 'gi.repository', but it's not. And then the 'else' import statement isn't working either.

Nor do I know yet, if client.py is purely broken there, or if software-properties-gtk isn't quite importing it correctly. Maybe there's a missing dependency that the developers had on their machine, but the reporters don't? But I've tried a few gobject packages and haven't hit on anything.

I'm still getting random closures when I try to update and if I try to access the"settings" to check what is set. I have used the terminal to do updates but the setting status doesn't seem to apply as some updates listed as "proposed" don't get updated but when I originally set the options I ticked that option on the original installation. I wanted to check this had not changed, hence my attempt to access the "settings".
John

after fresh dvdom install,update-grade and all the stuff we do when upgrading, me too confirming this one, its pretty annoying. some details, i had synaptic doing some installs, and like many here described i was browsing the software center, only other app i had was etherape and gkrellm but these are almost always on. it happened about the time i switched from docky/v.desktop2 to synaptic/v.desktop1 to see the console scroll-out.when i used the unity to switch, it didn't happen at all.

Paddy, that's good to note we have two versions of the file on our systems. For the moment, at least, we have "python-aptdaemon", and "python3-aptdaemon" packages in Quantal installs. It's the python3 file that's getting included by software-propeties-gtk. So fixing just